Insert for drilling strings



NOV 3, 1953 J. F. COCHRAN :TAL 2,657,907

INSERT FOR DRILLING STRINGS 'Filed July 2,4, 1950 Patented Nov. 3, 1953 UN ITED STATES PATENT OFFICE INSERT FOR DRILLING STRINGS Lafayette, La.

Application July 24, 1950, Serial No. 175,568

(CIL. Z55-28),'

11 Claims; l

This invention has?- to dov withy anr insertl for user in. a drilling string, that is', in' a stringv or assembly of equip-ment used in the drilling of? awelll such as an oil well, and it is a general object of the invention to provide a simple, practical, effective and safe device useful, generally, in a drilling string at or near the lower end thereof, as for instance, adjacentor in combination with the' bit or adjacent or in combination with a drill collar that maybe located above thebit'.

This application is filed as' a continuation in part of our application entitled Insert for Drilling String, led September 2f, 1949. Serial.Y No.. 113,754, now abandoned.

A general.' object off this invention. is to provide a device or' insert: applicable to a drilling string to occur between.y parts that are normally joined together, as for instance, between a. bit and the lower end of a drill collar; or between the upper: end". of a drill collar'and the lower` end of. a string of drill pipe, the` device being. such as to? project outward to bear upon or engage the wall of the well bore andy serve as a fulcrum or guide.

A general object ofY the invention is to provide an insert for adrillingstring ofthe general characterA referred to in which*l the-parts subject to wear or deterioration are readily replaceableor renewable, the construction being such that the necessary repairs for proper maintenance of the device may be made in-I the iield, as for instance, in the derrick located at the well where the structureis used.

Another object of this invention is toprovidean insert for a drilling string of: the. general character referredtoiwhich projkectsrint amanner; to'v engagethe wall; orV the; we1l.bore`= to1v provide a point of bearing in the ibore and which isso` formedv and constructed. that the projecting. parts may be easily andquickly reduced or. even possibly completely eliminated in thel event that it becomes necessary to relieve the drillingstring of the obstructions created thereby., feature is particularly importantwhen the structurev is used in the' drilling string at a point well above the bit; With the structure provided bythe in'- vention should the drilling' string become stuck it may be easily and quickly'released or-freed as by.: av washover operation in the courseof which the projecting portionl of thei'nsert may becut' away;

Another object of' the invention is to" provide an; insertVL of the generali' character' referred to applicable to` a drillingl string having-1 aa fluid? circulationl opening therethrough, which insert has a 'centrali iiow conducting passage corresponding insize and shapeV with thepassage' in. adjoining partsI oi" the string so thatV the insert does not restrict o'r impair flowthrough thestri'ngor the passage of 'instruments or equipment through the'v string'- when` such operations are necessary or desired.

A further objectoff this invention is to provide an insertV applicable to: a drilling string which is of` simple;v sturdy, dependable construe@ tion',` and which can be used to perform'v various functions or when various'operati'ons are desired. The insert can be so utilized' as to act, gener'- ally, asl` a stabilizer foi` the: drill pipe or itV can be used as a centrali'zing device forthe d'rillipipe;

` or-r it may be usedl as a; f'ulcrum on the; drill. pipe to have bearing on the wall of the Well bore, or. it may bev used. in situations whereY it,y in effect, combines such. functions or actions'. The structure may' in practices be.' used to advantage in operations such as hole straightening or deflec tion,- side tracking'or whipstocki'ng,. etc.

A further object of the invention: is to pro'- videI ai structureV of the' general. character. referred to ini which thev ribs: of drillable material are protected by caps of steel or thelike' which in'y turn mayw be hard-faced. the caps being formed' with or to theribs as Ibyv casting or forging so they are securely and dependablyv held.

The present' invention provides an insert for. a drilling string characterized byy an elongatetubular body,.the outside'of whichislround' in cross section, or turned; The body may bewof such' size" as to: correspond4 toY the parts of the stringA to-whichthe insert' is connected. The inside; or

,A bore oi? the: body correspondsf in size andshafpe withthe. circulation; openings# in. the adjoining. parts of the string andi: it is clear ortunobstructed; so' that it offers noobstructiom to fiuidlor elements requiredfto be passedatherethrou'gh;

Theinvention provides al plurality of elongatel ribs on the exterior of the bod-yg. which ribs are preferably straight, equally spaced.. around the body, and?l pitched relative to they longitudinali axis of the: body sothat they combineto provide 1 an. elective? guide centering the:bodyin1thewell bore.. The: ribs; are.A of limited'. extent' circumfferentiallyA or'inf.width, with theV result thatthe' structure provides large or wide-l spaces between the ribs-ta adequately handle circulation oifuidpast the'structure;

The invention provides a detachable mount-- ing for each; rib: soi that it can beremoved? from th'et body forreplacement or'repai'r when-neces# sary; Thefribsare preferably -formedof drillable' material.' s-uch'- asan'Vv aluminum' allby orthe like;

while the body is preferably formed of steel of a quality corresponding in strength and durability to that out of which the other elements of the drill string are formed. A shoe is anchored on the outermostl part or face of each rib and preferably extends over at least one end of the rib. The shoe is a wear-taking part preferably having an outer face surfaced with hard wear-taking material and is cylindrically curved. The shoes or wear taking parts when employed on the outer portions of the ribs are preferably cast with the ribs to be in effect integral therewith.

The various objects and features of our invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a view illustrating the insert provided by the present invention in a well drilling string near the lower end thereof, a unit embodying the invention being illustrated between the upper end of the drill collar and. the lower end of the string of drill pipe. Fig. 2 is a view showing the insert provided by the present invention located between the lower end of the drill collar and the bit and being used as a fulcrum to cause the bit to be deflected from a central position in the bore. Fig. 3 is an enlarged side elevation of the insert showing the details of construction employed therein. Fig. 4 is a view taken as indicated by line 4-4 on Fig. 3. Fig. 5 is an enlarged detailed sectional view taken as indicated by line 5--5 on Fig. 3, and Fig. 6 is an enlarged sectional view taken as indicated by line 6 6 on Fig. 3.

The device provided by this invention is intended for use in a well drilling string and in a usual application of the invention it is installed or incorporated in the drilling string near the lower end thereof. In the drawings in Fig. i one insert of the present invention is applied between the upper end of the drill collar A and the lower end of a string B of drill pipe. It is to be understood that we may use more than one insert in a single string and that the inserts when used may be located as circumstances require. In this particular case a reamer C is illustrated at the lower end of the drill collar to occur between the drill collar and a typical bit D. In the form of the invention illustrated in Fig. 2 the insert provided by the present invention is applied between the lower end of the drill collar A and the bit D so that the insert acts as a fulcrum allowing the drill pipe above the insert to lean to one side, say to the left as shown in Fig. 2, and thus cause the bit to lead off or bear in the opposite direction. These typical applications or installations of the insert are set forth to facilitate an understanding of how it can be used in practice, and are given as typical examples of use.

The insert provided by the present invention involves, generally, a body E with coupling means F at its ends, a plurality of ribs G carried by the body and projecting from the exterior thereof, the ribs being releasably secured to the body by mounting means H, wear-taking shoes J on the ribs, means K securing the shoes on the ribs, and various other features of construction and arrangement of parts as will be hereinafter described.

The body E in accordance with the present invention is a simple elongate tubular element, preferably formed of steel, or like material, such as is used in the other parts of the drilling string.

In the preferred form of the invention the outside I0 of the body E is round or turned concentric with the longitudinal axis of the structure, while the opening I I through the body is in the nature of a fluid passage or bore corresponding in size and shape with the fluid passages I2 in the other parts of the drilling string. The bore I I is shown as corresponding in size and shape with the fluid passages I2 in the adjoining parts of the drilling string and it will be apparent from the drawings that the bore I I is clear and unobstructed so that it does not retard flow of circulating fluid and permits ready passage of tools or instruments as circumstances may require.

The coupling means F occur at the ends of the body E and are provided for releasably coupling the insert with the other parts of the string. In the case illustrated the coupling means F at the lower end of body E is in the form of a threaded pin I5 while at the upper end of the body it is formed by a threaded socket I6.

In accordance with the present invention a plurality of ribs G are provided to occur on the exterior of body E so that they project radially outward therefrom, and although the ribs may vary in number, form and design, it is preferred that there be but three ribs spaced 7 apart around the body and that they be pitched so that they are angularly disposed relative to the longitudinal axis of the body, preferably at about 30 thereto. It is preferred that the several ribs be straight elongate elements of considerable length and also of substantial width. The ribs are spaced a substantial distance apart so that there are substantial openings or channels at 20 between adjacent ribs providing adequate means for handling fluid that must circulate past the ribs.

In accordance with the present invention each rib is an elongate body or block of drillable material and is generally rectangular in cross sectional configuration so that it has flat parallel sides 2| and a top 22. In practice the ribs may be formed of various materials subject to being drilled or disintegrated. In accordance with the invention the ribs are formed of a material such as an aluminum alloy that can be readily drilled up or destroyed by cutting tools ordinarily employed in drilling. When the term "drillable material is used we mean to refer to or to include material or materials of such character as to be subject to removal by means of the general character operable in weil bores.

'I'he mounting means H for each rib G secures the rib to the body E so that it projects from the exterior of the body and is disposed at the desired angle. In the preferred form of the invention the mounting means H is such as to releasably hold the rib so that it may be detached from the body and is rigid on the body during operation of the structure. In the preferred form of the invention the mounting means H involves a tongue and groove construction and as shown in the drawings a groove 30 is cut in the exterior of the body E at the desired angle and to the desired depth, while the inner portion 3I of the rib G is in the nature of a tongue which seats in and occupies the groove. In the case illustrated the bottom portion of the groove 30 is enlarged or undercut at 32 and the tongue portion 3l is flared or enlarged to fit into the undercuts. The bottom 38 of groove 30 is preferably flat and the rib has a flat bottom that seats or bears on the bottom 38. The manner in which the tongue engages and ts the groove is 'clearly illustrated in Fig. 5 of the drawings.

In the preferred form of the invention the groove 3i! in the body is slightly tapered or -convergent so that itis narrower at its upper end than at its lower end and the tongue yportion 3l is correspondingly shaped or tapered so that it has a Wedging engagement in the groove. In the par ticular case illustrated the entire rib is 'tapered to correspond with the tongue.

Olne or more stops are Vprovided to ypositively retain the rib in engagement with the body and in the form of the invention illustrated a stop 3Q engages one end of the rib and a stop 46 engages the other end of the rib. The stops 39 and il may be in the nature of blocks engaged in sockets or recesses il in the bottom 38 ofthe groove 3Q where they are suitably retained to project up from the bottom and thus confine the rib in the groove. Stop 35 engaged by the upper end of the rib is preferably xed in place as by welding whereas the stop 40 is releasable or removable, Stop de is shown held in place by a screw fastener. The stop blocks are preferably elongate in form and are disposed so that they extend transversely of the groove Si! as shown in Fig. 3 of the drawings. It will be apparent that the block 39 at the upper ends of the rib may be eliminated if desired since the tapered construction prevents passage of the rib upward beyond the position shown in the drawings.

In the form of the invention illustrated there is a single wear-taking member or shoe J on the outer face 22 of each rib G and this shoe covers the face 22 and has an end extension that covers an end of the rib. Shoe J is preferably formed of wear resisting material such as steel and its outer face is preferably surfaced with hard-facing material t6, or the like. The outer surface SS of the shoe, occupied by the hard-facing, is curved so that it is concentric with the central longitudinal axis of the tool. In practice the -hardfacing 46 may be tungsten carbide or other suitable material secured or applied to the shoe J in any suitable manner. The extension 41 of the shoe is integral with the portion of the shoe that covers the outer face of the rib and it occupies all or part of one end of the rib. In the preferred construction both ends of the rib are beveled off or inclined and the extension is like- Wise inclined and covers or protects a substantial portion of the lowermost end of the rib. The beveled ends of the rib prevent the insert from catching as it is moved lengthwise in either direction and the shoe part protecting the lower end of the rib prevents wear of the rib at that end under normal operating conditions.

In practice we prefer to form the shoes for each rib as a casting and the means K joins each shoe to its rib so that these parts are rmly and rigidly connected. We contemplate that in some cases the shoes may be shaped or worked as by bending or forging so that they are properly secured to or on the ribs. In the preferred construction a pair of longitudinal parallel ridges 59 project from the outer face The ridges are spaced apart and have inner sides or edges 5l that are opposed and which defines an undercut r dove-tailed channel which is occupied by a projection 52 on the inner side of the shoe J. The outer sides 54 of the ridges are inclined or outwardly convergent and the shoes have side portions 54 that overlie the outer sides of the ridges.

In manufacture we cast the drillable material to the previously cast shoes and as a result the material of each rib shrinks onto the projection 52 of the shoe of that rib so that the joinder between the shoe `and rib is solid yand permanent. If desired the structure of means K can be continued along the extension of each shoe and there may be cases in which we provide extension of the shoes at both ends thereof.

From the foregoing description it will be observed that the construction provided by the present invention is simple, inexpensive and sturdy. The ribs being detachable or separable from the body can be renewed or replaced when necessary and the ribs vand their shoes, being formed by casting, are inexpensive of manufacture. Renewal or replacement of the ribs can be easily performed at the derrick or the point where the structurels used.

It will be apparent that the insert can be used in a drilling string at various points, for instance, in a manner such as is shown in Fig. l, or as shown in Fig. 2, and when in use the cylindrically curved outer faces 46 of the shoes afford effective and substantial bearing engagement with the wall of the bore where the bore corresponds in diameter with the insert. It will be apparent that the insert may be used or may act as a stabilizer, centralizer or fulcrum. In the event that the drill pipe should twist off or become stuck and material should lodge around the insert so that the projecting ribs thereof interfere with removal of parts of ythe string, a wash-over tool can be operated over the insert and a cutting tool can be readily operated in such manner as to remove or cut away the ribs. In the case of such an operation the steel shoes J may not be out or broken up but they become disengaged, and being relatively small, are not serious obstructions.

Having described only a typical preferred form and application of our invention, we do not wish to be limited or restricted to the specic details herein set forth, but wish to reserve to ourselves any variations or modifications that may appear to those skilled in the art and fall within the scope of the following claims.

Having described our invention, we claim:

1. An insert for use in a drilling string with a central longitudinal flow conducting opening therethrough including, an elongate tubular steel body corresponding in koutside diameter with the drilling string and defining a flow passage corresponding in size with the opening through the string, a plurality of elongate drillable ribs, means detachably mounting the ribs on the exterior of the body in spaced relation around the body and projecting outward from the body and at an angle to the longitudinal axis of the body including tongues on the ribs held in grooves in the body and stops holding the tongues against displacement from the grooves, a plurality of shoes, and means mounting the shoes on the outer faces of the ribs including, ridges on the ribs embracing projections on the shoes, the outer faces of the shoes being cylindrically curved concentric with the central longitudinal axis of the body.

v2. An insert for use in a drilling string with central longitudinal f flow conducting opening therethrough including, an elongate tubular steel body corresponding in outside diameter with, the drilling string and defining a flow passage correspending in size with the opening through the string, a plurality of elongate .drillable ribs, means detachably mounting the ribs on the exterior of the body in spaced -relation around the body and projecting outward from the body and at an angle 7 to the longitudinal axis of the body including tongues on the ribs held in grooves in the body and stops holding the tongues against displacement from the grooves, a plurality of shoes, and means mounting the shoes on the outer faces of the ribs including, converging ridges on the ribs embracing projections on the shoes and confined between sides of the shoes, the outer faces of the shoes being curved concentric with the central longitudinal axis of the body, each shoe covering the outer face of its supporting rib and having its outer face covered with hard facing material.

3. An insert for use in a drilling string with a central longitudinal flow conducting opening therethrough including, an elongate tubular steel body corresponding in outside diameter with the drilling string and defining a flow passage corresponding in size with the opening through the string, a plurality of elongate drillable ribs, means detachably mounting the ribs on the exterior of the body in spaced relation around the body and projecting outward from the body and at an angle to the longitudinal axis of the body including tongues on the ribs held in grooves in the body and stops holding the tongues against displacement from the grooves, a plurality of shoes, and means mounting the shoes on the outer faces of the ribs including, ridges on the ribs and having converging opposed sides embracing projections on the shoes, the ridges being within side portions of the shoes, the outer faces of the shoes being curved concentric with the central longitudinal axis of the body, a stop at one end of each shoe secured thereto by Welding material, and keys making the shoes tight on the ribs.

4. An insert for use in a drilling string having pipe sections and separable elements larger in diameter than the pipe sections, the insert being adapted to be arranged between said elements and including, an elongate tubular steel body of substantially the same outside diameter as said elements and having coupling means at its ends adapted to connect with said elements to be vertically disposed in the drilling string, a plurality of elongate ribs of drillable material, means detachably mounting the ribs on the exterior of the body to extend longitudinally of the body and at an angle to the longitudinal axis of the body, the ribs being in spaced relation around the body and projecting radially outward from the body, and shoes of wear resisting material on the outermost faces of the ribs adapted to resist wear as the insert is operated with the drilling string, said means including a tongue on each rib extending longitudinally thereof and held in a groove in the exterior of the body extending at an angle to the longitudinal axis of the body, the groove being transversely undercut and being longitudinally tapered so that it is upwardly convergent and the tongue being of the same shape as the groove to wedge tightly therein, the ends of each rib being beveled so they converge as they extend radially outward from the body, the ribs projecting radially of the body to facilitate operation of a wash-over and cutting tool to cut the ribs between the body and shoes.

5. An insert for use in a drilling string having pipe sections and separable elements larger in diameter than the pipe sections, the insert being adapted to be arranged between said elements and including, an elongate tubular steel body of substantially the same outside diameter as said elements and substantially uniform in size and shape from one end to the other, the body having coupling means at its ends to connect to said elements, the body having circumferentially spaced grooves entering it from its exterior and extending at an angle to the longitudinal axis of the body to have like circumferentially spaced open ends, a plurality of elongate ribs of drillable material, means detachably mounting the ribs on the body so the ribs project from the exterior of the body in spaced relation around the body including a tongue on each rib extending longitudinally thereof and held in one of the grooves in the exterior of the body and a stop in the groove at each end of the tongue holding the tongue against movement longitudinally in the groove, the ends of each rib being beveled so they converge as they extend radially outward from the body, and shoes of wear resisting material on the outermost faces of the ribs adapted to resist wear as the insert is operated with the drilling string, the ribs projecting radially of the body to facilitate operation of a wash-over and cutting tool to cut the ribs between the body and shoes.

6. An insert for use in a drilling string having pipe sections and separable elements larger in diameter than the pipe sections, the insert being adapted to be arranged between said elements and including, an elongate tubular body of steel of substantially the same outside diameter as said elements, the body having coupling means at its ends adapted to connect the body to said elements to be vertically disposed, a plurality of elongate ribs of drillable material, means detachably mounting the ribs on the body to extend longitudinally thereof and at an angle to the longitudinal axis thereof and to project from on the exterior theerof, the ribs having parts facing radially outward of the body and having inclined ends facing downwardly and outwardly, and wear-taking shoes on the outwardly facing parts of the ribs, the shoes having curved faces concentric with the central longitudinal axis of the body and having lower end portions extending inwardly toward the body at the ends of the ribs, the ribs projecting radially of the body to facilitate operation of a wash-over and cutting tool to cut the ribs between the body and shoes.

7. An insert for use in a drilling string having pipe sections and separable elements larger in diameter than the pipe sections, the insert being adapted to be arranged between said elements and including, an elongate tubular body of steel of substantially the same outside diameter as said elements and adapted to operate in a vertical position, a plurality of elongate ribs of drillable material, means detachably mounting the ribs on the body to extend longitudinally thereof at an angle to the longitudinal axis thereof and to project from the exterior thereof, the ribs having inclined upper and lower ends that converge as they project radially outward from the body, elongate wear-taking shoes, and means mounting the shoes on the outermost parts of the ribs to extend longitudinally of the ribs and including ridges on the outer faces of the ribs embracing projections on the shoes, each shoe having an end extension projecting inwardly toward the body at the lower end of its supporting rib, the ribs projecting radially of the body to facilitate operation of a wash-over and cutting tool to cut the ribs between the body and shoes.

8. An insert for use in a well drilling string having pipe sections and separable elements larger in diameter than the pipe sections, the

insert being adapted to be applied between and to connect said elements that are larger than the pipe sections and including, an elongate steel body round in cross section and of substantially the same outside diameter as said elements and having a central longitudinal opening through it adapted to conduct fluid from one of said elements to the other, a plurality of circumferentially spaced ribs of drillable material carried by the body and projecting radially therefrom, and shoes of wear resisting material on the outermost faces of the ribs adapted to resist Wear as the insert is operated with the drilling string as a guide therefor and to be severed from the body by cutting of the ribs, the ribs being of such extent radially of the body as to facilitate operation of a \vash-over and cutting tool to cut the ribs between the shoes and the body.

9. An insert for use in a well drilling string having pipe sections and separable elements larger in diameter than the pipe sections, the insert being adapted to be applied between and to connect said elements that are larger than the pipe sections and including, an elongate steel body round in cross section and of substantially the same outside diameter as said elements and having a central longitudinal opening through it adapted to conduct uid from one of said elements to the other, a plurality of circumferentially spaced ribs of drillable material carried by the body` and projecting radially therefrom, and shoes of Wear resisting material on the outermost faces of the ribs adapted to resistwear as the insert is operated with the drilling string as a guide therefor' and to be severed from the body by cutting of the ribs, the body being substantially uniform in diameter from one end to the other and the ribs being the only parts projecting from the round exterior of the body and projecting radially from the body to facilitate operation of a wash-over and cutting tool to cut the ribs between the shoes and body.

10. An insert for use in a well drilling string having pipe sections and separable elements larger in diameter than the pipe sections, the insert being adapted to be applied between and to connect said elements that are larger than the pipe sections and including, an elongate steel body round in cross section and of substantially the same outside diameter as said elements and having a central longitudinal opening through it adapted to conduct fluid from one of said elements to the other, a plurality of circumferentially spaced elongate ribs of drillable material carried by the body and projecting radially therefrom and extending longitudinally thereof and pitched relative to the longitudinal axis thereof, and shoes of wear resisting material on the outermost faces of the ribs adapted to resist wear as the insert is operated with the drilling string as a guide therefor and to be severed from the body by cutting of the ribs, the ribs being of such extent radially of the body as to facilitate operation of a wash-over and cutting tool to cut the ribs between the shoes and the body.

11. An insert for use in a well drilling string having pipe sections and separable elements larger vin diameter than the pipe sections, the insert being adapted to be applied between and to connect said elements that are larger than the pipe sections and including, an elongate steel body round in cross section and of substantially the same outside diameter as said elements and having a central longitudinal opening through it adapted to conduct fluid from one of said elements to the other', a plurality of circumferentially spaced elongate ribs of drillable material carried by the body and projecting radially therefrom and extending longitudinally thereof and pitched relative to the longitudinal axis thereof, and shoes of Wear resisting material on the outermost faces of the ribs adapted to resist wear as the insert is operated with the drilling string as a guide therefor and to be severed from the body by cutting of the ribs, the ribs being of such extent radially of the body as to facilitate operation of a wash-over and cutting tool to cut the ribs between the shoes and the body, the shoes being substantially coextensive with the outermost faces of the ribs and having exposed wear resisting facings uniformly curved about the central longitudinal axis of the body.

JOHN F. COCHRAN. JONATHAN I. MIDDLETON. NORMAN D. JAQUES.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,516,914 Croft et al. Nov. 25, 1924 1,605,316 Wilson Nov. 2, 1926 1,937,742 Brink Dec. 5, 1933 2,084,421 Wright June 22, 1937 2,288,124 Creighton June 30, 1942 

